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Class Y>r 51S 

Book ^rV]_ 

Copyright N" 



COPYRIGHT DEPOSIT. 






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SILKWORn REARING 



AS A PASTIME=== 



(WITH SIX ILLUSTRATIONS) 




Dr. CECIL FRENCH, Naturalist 



WASHINGTON, D. C, U. S. A. 



COPYRIGHT 1905. BY CECIL FRENCI- 



Jwo Copies Hece/veu 

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7 



Silkworm Rearing as a Pastime 

By Dr. CECIL FRENCH, Naturalist. 

WASHINGTON, D. C. 

PREFACE 



'^HIS little booklet has been written as a practical guide 
^ for the amateur Silkworm Culturi-t, to afford an ele- 
mentary course of instruction in the successful pur- 
suit of a most delightful and fascinatmg pastime, it is 
not intended for the professional sericulturist and no at- 
tempt has been made to treat the subject from a scientific 
or technical standpoint. Indeed, were I to attempt the lat- 
ter 1 should feel 1 were treading upon hallowed ground, for 
classical instruction in the industry is a matter of history, 
referred to by Aristotle and having its being at least four 
thousand five hundred years ago in China, the country in 
which the domestication of the insect is generally believed 
to have had its inception. What 1 have written here is the 
record of my own experience, a description of the methods 
by which a great amount of amusement can be had. To 
he professional sericulturist these methods will be open to 
.iticism, but the pursuit of a pastime should have no pe- 
cuniary benefit in view, and if I do not advocate the ob- 
servance of hard and fast rules and attention to minor 
details, it is because I wish to avoid making the pastime 



irksome. At the same time I should remind my rea^ 
that whilst the instruction here imparted applies to 
rearing of the domesticated silkworm on a small scale 
the home, there are many species of silkworms, differing 
from each other in certain of their habits, and the metho. 
of rearing advocated in the following pages is a modifica- 
tion of the methods practised on a large scale by the pro- 
fessional sericulturists. 

Aside from the ample reward that will be found in 
knowledge gained of the marvelous workings of nature 
and the absorbing interest that wiM be aroused, a quantity 
of beautiful silk can be produced which may be put to such 
use as bookmarkers. I remember as a boy how I used tc^ 
steal from my bed on the tiptoe of expectancy in the small 
hours of the morning to watch for the first appearance of 
my little brood of spinners, and later with what pleasure L 
presented to my mother and sisters the skeins of beautiful 
silk. There was no lagging of interest, for the lifetime of 
the little busybodies was far too brief. 

In houses with limited room, the raising of more than 
a hundred worms will prove impracticable and should not 
be attempted, and even this number will require an aston- 
ishing amount of space. 



CARE OF THE EGGS. 

■.^he first essential is proper care of the eg-g-s. These are re- 
ceived either g-rouped ill clusters adheretii to paper or other ma- 
terial or loose like seeds in a packet. They are of a dull yrey or 
'^•htly erreenish tint, thougrh when first laid are yellow. Life 
'thin them remains dormant from autumn of the precediiig 







HE EGGS— The essfs, when spread out to hatch should not be bunched 
as much as they appear in this picture but should be more scattered. 

season until about February or March according- to the climate. 
Under normal conditions when the temperature rises above EQ^ F. 
development of the embryo commences and it will be readily un- 
derstood that some provision must be made to protect the delicate 



ernbr3o from sudden climatic cliang-es and particularly to j^uard 
ayainst premature hatching- in the artificially heated rooms of the 
average house. Fortunately, most households maintain an ideal 
place, namely-, a refrigerator. The eggs should be placed in a 
small tin box in which the e are holes punctured for ventilation, 
and deposited in the refrigerat»,r until the time for hatching 
arrives. 

HATCHING THE EGGS. 

With the advent of warm weather and the appearance of vege- 
tal ion, pr.-parations must be made for the hatching of the brood. 
There is no betttr way of determining the right time than by 
watching for the budding of the mulberry trees. If there are uo 
mulberrj' trees at hand to observe, the latter part of April may 
be chosen in the milder climates and the earl3' part of May in 
more northerly regions; but, in any case, the suppl3' of food must 
be secured. 

In the large establishments proper temperature is considered 
a very important matter, for upon it will depend the rapidity of 
incubation and the regularity and percentage of hatchings Incu- 
bators are used just as they are in chicken hatcheries, and a tem- 
perature of round about 70* F. is maintained. But for parlor cult- 
ure the ordinarv living room temperature will suffice, though, 
if the nights threaten to bring about any great variation, it is. 
better to place the eggs where they will keep warm. 

Humidity is also considered an important matter just as it is 
in the hatching of chickens. However, I never pinned much faith 
on this, but no harm is done in sprinkling a little warm water in 
the vicinity of the eggs, or better still, in keeping a shallow dish 
of water near them. 

The eggs are set out to hatch in the light but on no account in 
the direct rays f the sun. If the egg^ are separatelike seeds they 
should be spread out in a thin layer upon sheets of blotting-paper. 
In about seven or eight days and sometimes even earlier (the 
length of time depending on temperature) the first hatchings take 
place. The period of incubation, when hatchings are undertaken 
out of season, as for instance, in the winter months, is somewhat 
longer, averaging three weeks. The imminence of hatching can 
be determined by the whitening of the eggs. Without the aid of an 
incubator the hatchings are always more or less irregular and ex- 
tend over a week. The first worms to put in an appearance aire the 



strong-est and all worms emerg-lnfr after Ihe fourth or fifth daj- 
should be destroyed as they are g-enerally weakly and not worth 
the trouble of rearing-. In an irreg-ular hatching, which is una- 
voidable without the aid of an incubator, two colonies should be 
formed, the earlier and better developed worms beiujr segre- 
g-ated into one, the more tardy ones into the other. The hatchings 
take place mostlj- in the earlv morning- hours, between 4 and 9 
o'clock, so that he who would observe the process must be up 
betimes. 

FOOD SUPPLY 

If there is any one distinguishing- feature of the silkworm's 
life it is the remarkable capacity of this little creature to eat. The 
greediest hog cannot surpass it in voracity. In the active phases 
of its development its prime object seems to be toeatboth day and 
night. But we do not begrudge it this capacious appetite when 
we remember what it portends — the storing up of the energy- and 
material necessarj- for the wonderful work of silk production. In 
fact, the more food we can encourage the little cr ature to crowd 
into itK alimentary canal during its brief lifetime, the greater may 
we expect the yield of silk. 

As I have already pointed out, the food suppl3' must be secured 
in anticipation of the hatchings. The natural forxl of the silk- 
worm is the mulberry leaf. There are man vvarietiesof mulberry 
trees, but the best for the purpose is the White Mulberry which is 
to be found in many parts of the United States. However, mul- 
"berry leaf is not absolutely necessary for the nourishment of the 
silkworm, for I have raised them on lettuce leaf, which thej- will 
eat with relish, when, for some reason or other mulberrv leaf was 
not obtainable. Thej' can even be kept alive for a time on Ihe leaf 
of the dandylion and one or two other plants, amongst them the 
Osage orange, but of this latter the young and succulent leaves 
should not be fed But none of these substitutesenables the worm 
to thrive and produce the quality or quantity of silk that it does 
from the mulberry. Therefore, every effort should be made to ob- 
tain a supply of mulberry leaf. If the culturist resides in the city 
he must solicit the aid of some friend in the country or make ar- 
rangements with some nursery. Mulberry leaves can be easily 
sent from one point to another by mail. A fresh supply should be 
obtained at least once a week. The leavescan be kept fresh a few 
days by putting them in a jar and covering the latter with a damp 



cloth. But the leaves must not be allowed to pet wet or heated as 
such conditions are highly conducive to disease. Tlie blossoms 
and berries must be discarded and onl\- healthy looking- leaves 
provided. If leituce is used it must be Ihorong^hly dried and cut 
up in small pieces. 

How often should the worm be fed? In China feeding- opera- 
tions are actually undertaken ever^- half hour. In this country 
and in Europe it is customary in the large establish nients to adopt 
regular hours for feeding-, beginning very earl^v in the morning- 
and ending late at night. The food (leaf) is also cut up into small 
pieces. But for parlor culture such niceties are b.v ro means im- 
perative. It is possible to provide at one feeding sufficient leaf to 
carry each individual through the succeeding twent3'-four houis. 
In fact, in my bo3'hood days this scant attention was frequently 
all that my broods received. A safe rule is to keep pace with the 
creature's appetite, remembering- that it is in the early hours of 
the morning when its appetite is keenest, that it is most in need of 
a bountiful supplv of food. I have never found mincing- or chop- 
ping up of the leaves necessary, though this little attention is per- 
haps helpful to the tender worm in the first stag-e of its existence, 
because its sustenance is obtained from the juice of the leaf at first. 

THE NURSERY 

In what kind of rearing place should the wormsbekept ? The 
lid of any old cardboard box answers the ])urp<)se admirably and 
as the worm increases in size the box itself should be used. The 
top is left open and there need be no fear of any of the worms es- 
caping or wandering far as long as there is a supply of food within. 
But let the food suppU* once diminish aud out will crawl the 
creature in search of a more congenial environment. Several of 
these extemporized trays should be kept at hand for not im\y will 
they be needed to afford a frequent transfer to clean (juarters but 
the rearing space will have to be increased as the germs enlarge. 
Any odd shelf or window sill out of the sun's rays will suffice as 
a depository for the trays. A room should be selected which is 
not subject to draugrhts or variations of temperature but at the 
same time admitn of free ventilation. Living room temperature is 
most suitable. 

It need hardly be mentioned that throug-hout the life of the 
worm its surrounding-s must be kept as clean as possible. If ex- 
crement is allowed to accumulate in the bottom of the tray unhv- 



g-ienlc conditions are created which are a fertile source of disease. 
Frequent changes to clean quarters are necessarj-. 

To save time and labor in effecting- the daily transfer of hund- 
reds of worms, a device is made use of in the form of a net having- a 
mesh of a size suitable to the ag-e of the worm and stretched upon 
a wooden frame. At nig-ht time the last meal is distributed over 
the net and the latter is extended over the worms. During- the 
nig-ht the ever-hung-r3' worms, scenting- the fresh leaf, desert their 
stale feeding- ground and find their way up through the meshes. 
The entire colony is then lifted wholesale and deposited in clean 
quarters. But on a small scale such facilities can be dispensed 
with. The ver.v small worms may be picked up and moved with a 
(genuine) camel's hair brnsh, whilst the larger worms may be 
transferred with the fingers. If gentleness is observed thei e need 
be no fear of injuring the worms. The first change of quarters 
should be made about the fourth da_v. 

THE PHASES OF LIFE 

When certain stages of development are reached the silkworm 
undergoes a process known as '* molting," when the entire skin is 
shed. Four of these molts take place at intervals of a few da.vs, 
during which there is a suspension of activity, thus dividing the 
active life of the animal up into five distinct phases. 

First Phasb— The hatchings having taken place the newly 
t)orn youngsters are picked up with a camel's-hair brush and 
placed in the tray in which there has previously- been evenly dis- 
tributed a layer of finely cut up leaf. An ample supply of food 
being furnished, development proceeds apace until about the fifth 
day, when the worm is observed to lose its appetite and become 
sluggish. This inaction usually creates disappointment or appre- 
hension in the mind of the novice if he has not previously fortified 
Ihimself with the knowledge of what is impending. lu a few hours 
the worm ceases to eat altogether and appears to lose flesh, its 
«kin becomes shiny and it attaches itself to the stem of a leaf or 
other convenient point and remains motionless with its head 
raised. Less food is no-w required for the remainder and none at 
all if every worm in the colony is molting at the same time, but as 
this rarely happens, food must be provided for those that are in an 
active state. From twenty-four to fort3-eight hours are spent in 
ridding itself of its old skin which it does b3' crawling out for- 
wards. If touched during this period it shakes the forepart of its 
body. 



Second Phase — On coming' out of the molt, the worm, which 
has now assumed a greyish color, looks around for food. At this 
stage increased space must be provided and it is better to further 
divide up the worms, putting- all the forward ones in one tray and 
the backward ones in another. About the fourth day they should 
all be transferred ag-ain to clean quarters. The second phase lasts 
about five or six days when the worms again enter upon a molt. 

Third Phase— This is very similar to the first two and treat- 
ment should be along the same lines but with an increased suppiy 
of food, for the worms now grow very perceptibly-. In color they 
become much paler. About the fifth day change of quarters must 
be made and on the sixth or seventh we look for the third molt. 
Strang-elyenoug-h, this molt and the fourth phase of the creature's 
life are the most critical, when diseases are prone to develop. 
During- the chang-e it is important to keep the surroundings as dry 
a d clean as possible. 

Fourth Phase— In this phase the worm eats more than ever 
and large (juantities of leaf must be provided. Chang-e to clean 
quarters must also be made more often, and as of ten as the chang-e 
is made the space should be increased. I'anicular care must also 
be bestowed on the selection of the leaf, avoiding any that is damp 
or mold\'. The fourth and last molt takes place about the sixth 
day. 

Fifth Phase— This is the most interesting- of all when re- 
turns may be looked for. The worm now eats a prodigious quan- 
tity of food and g-rows astonishing-l^', and the object should be to 
encourage it to stuff itself to the utmost limit. Fifty worms dur- 
ing- this phase will eat from three to five ounces of leaves daily. 
Chang-e to clean quarters must now be made dail3-, and the space 
still further increased. In about six or seven days, sometimes 
long-er, the appetite beg-ins to diminish, the worm appears to 
shrink, and it assumes a transparent color. In two or three daj's 
feeding- is altogether suspended aud the worm acts in an uneasy 
manner, crawls aimlesslj' up and about and raises and moves its 
head to and fro as if seeking- something-. In realitj- it is looking- 
for a convenient place to spin. A corner of the box is g-enerally 
selected though it will sometimes wander bejond the confines of 
the latter, always going- upwards. Soon H beg-ins tothrow around 
it a loose "cobweb" of silk. At this point it must be carefully 
transferred to a spinning place. The best depository for this pur- 
pose is a paper cornucopia about five or six inches in leng-th. 



Each worm is provided with its own individual refuge and the 
cornucopias may be pinned to the wall in a row. As a rule the 
worm will gratefully remain where it is placed and at once pro- 
ceed to carry out its task. If it does not remain within its refug'e 
it is a sign that it is not jet readN- to spin and it should be returned 
to its feedinjj- (|uarters. 




A Colony of well-frrown Worms hard at work devouring: mulberry leaves 
The worm^ are too crowded in this picture. N ore space should be al- 
loted than is here shown. 

If the worm is watched in the process of spinninj"- it will be ob- 
served ceaselessly moving- its head to and fro in the act of running- 
the thread of silk backwards and forwards in an irregrular manner. 
Durinjr the first si.x hours an outer loose web-like structure is 



thrown around itself. In the ceiiler of this it then proceeds to spin 
around itself the compact cocoon proper. The process lasts some 
three days and during- this time it moves its head to and fro some 
250,000 times and paj's out a half mile or more of delicate ffolden 
cable. An idea of the e.Ktreme delicacy of this fiber mav be 




Paper Cornucopia containine: a cocoon surrounded by its floss. The cor- 
nucopia is always intact; a hole has been cut in it in this instance in 
order to afford a glimPse at the cocoon. 

gathered from the fact that it takes from sixty to one liundred 
single fibers to make the thickness of ordinary sewing- silk. The 
silk which the creature elaborates is the product of a semi-fluid 
g-landular secretion which hardens on exposure to the atmosphere. 
It comes from the worm iu two microscopic strands which adhere 
firmly tog-ether. 

10 



Within the cocoon in the course of the next seven or eif^ht da3-s 
the wonn or larva underg-oes its transformation into the chrysalis 
stale, and during this period passes through a sort of fifth'molt. 
It sheds its skin and remains motionless. In from two to three 
weeks from the time spinning- is commenced, if it is left undis- 
turbed, it will have developed into a moth which will at once begin 
to eat its way through the cocoon at the expense of the latter. 
This brings us to the consideration of what to the amateur is a 
ver_v important matter, viz: 

DISPOSITION OF THE CCCCON 

The technical works all teach that certain of the cocoons 
should be set aside for propagating purposes, the finest cocoons 
from worms which have been the earliest to spin being selected 
and carefull3' laid awaj' and the moths allowed to eat their way 
out in a natural manner, This means, of course, that the silk 
from these particular cocoons cannot be utilized, for in the act of 
its emergence the worm necessarily destro3'S the continuit3' of the 
thread. The balance of the cocoons forming the main harvest are 
then subjected to the fumes of bisulphide of carbon or to steam for 
the purpose of killing the chrvsalid?s. This is done in order to 
prevent the moth from eating its wa3- out and destroying the silk 
before the latter can be reeled. It is a necessarv step where a 
large number of cocoons is to be dealt with and the silk cannot be 
reeled within the limited time prior to the tiioth's appearance. 

Thus, it will be seen that the professional methods entail the 
loss of part of the silk harvest on the one hand and a number of 
breeding moths on theother. Now, to the amateur this is a matter 
of no small concern. In an3' case his harvest of cocoons and 
moths wherewith to propogate his stock is limited and he wants 
"to get all that is coming to him." It takes the reeling of at least 
eight or ten cocoons to make a skein of raw silk worth having. 

As a matter of fact the professional method of treatment at 
this stage would be, for a limited number of cocoons, highly e.x- 
traA'agant; it would virtuall3' be throwing away part of what it has 
taken so much pains to produce. It is possible to utilize the silk 
from ever3' cocoon aud at the same time save ever3^ moth for 
propagating purposes, but to accomplish this it is necessary to 
reel the silk soon after spinning, has been completed and to care- 
fulU' harbor the chr3'salis in suitable surroundings where it ma3' 
continue to undergo transformation into its tinal phase, that of the 
moth. 

LofC. 



REELING THE SILK 

I have already noted that ittakes some seven or eight days for 
the worm to complete the cocoon. It can easily be ascertained 
when <his stag-e has been reached by shaking- the cornucopia con- 
taining- the cocoon. If there is a rattling- within the time for reel- 




Reeling^ the silk by means of a strip of cardboard. 

ing is ripe. The cocoon is thereupon removed from the cornucopia 
and the outer cobweb-like floss pulled off. It is next placed in a 
bowl or tumbler of moderatel3' hot water such as can comfortably 
be borne by the hand After lying- in the water a short time it is 
taken out and whisked over with a small stiff brush (a nail brush 

12 



will answer the purpose) until the end of the thread is caug-ht up. 
The end of the thread can also be secured bj' picking with the 
finyers at the surface of the cocoon. The cocoon is then dropped 
back in the water and the reeling- proceeds. If during- the reeling- 
the thread does not come away freely, but catches and lifts the 
cocoon out of the water, it is an indication that the water is not 




A bkein of S ilk in use as a Bookmarker. 

hot enoug-h to dissolve the g-um-like matter to which the cohesion 
of the coils of silk is due, and hotter water must be added, but thi.9 
should be done cautiously and the water not made too hot, or there 
is dang-er of the chrysalis being- killed. A simple way to keep the 
cocoon from coming- out of the bowl is to lay a heavy piece of card- 

13 



board over the top of the latter, allowing- only a small open space 
for the thread to pass through. The jar sustained by the cocoon 
on coming- in contact with the cardboard is sufficient to disengage 
the thread and cause the cocoon to fall back into the water. The 
reeling is continued until practically- no thread remains and wt 
come upon a flimsy silken skin enveloping the chrysalis. Of 
course, the thread will sometimes break, in which case the broken 
end is caught up and the winding continued. 

For reeling the silk many devices have been invented and 
with a lift e skill and a few tools an inexpensive winder can be 
constructed. But for limited use such adjunct can be dispensed 
with and the silk reeled off on a strip ..f cardboard about five 
inches in width and eight in ength as shown in the accompany- 
ing illustration. When five or six cocoons have been reeled off 
to form one skein the latter is removed from the cardboard. To 
convert it into a bookmarker it only remains to tie it in a knot in 
the center. 

TREATMENT OF THE CHRYSALIS 

It must be remembered that b^' disrobing the chrysalis of its 
protective coating of silk we subject it to an unnatural condition 
and the very first thing we need to do is to afford it an artificial 
covering. This difficnlty is easily overcome by the employment 
of bran. The ever useful cardboard box is again brought into 
requisition and filled with the bran in the depths of which the 
chrysalis is buried after removing it from the aforementioned 
flimsy skin. This chrysalis is golden colored at first but soon 
turns to a chestnut brown. The bran and its contents must be 
deposited in a warm place. 

When tbe development of the chrysalis into the moth is com- 
plete the external shell bursts asunder and out crawls the moth. 
This taUes place in the early hours of the morning. As soon as 
possible the moths must be transferred to another cardboard box 
on the bottom of which a sheet of stout paper has been laid. The 
lid may be left off as the moths cannot fly in the air and they do 
not need any nourishment at any time of their brief existence. 

Shortly after emerging the moth excretes a fluid matter and 
then union of the sexes takes place. This lasts several hours 
when the moths separate and the female soon starts in to lay her 
eggs on the paper. The female can alwaj's be distinguished from 
the male by her larger abdomen and the male from the female by 

14 



»^otistant fltfttering-of his wing's- Aboat three or four hundred 
eg-g-s are laid by each female in the course of three da3's, the ma- 
jority being- deposited at the start. Then, in a few hours' time 
the strenuous life of the liitle creature is brought to a close by its- 
-ath. 




The Moths shortly after emergence from the Chrysalis. 

Finally, the strips of paper to which the eg-gs are adherent are 
gathered up and stored away where there is no artificial warmth 
until the following season. 

DISEASES 



A description of this sort would not be complete without a 
brief reference to the diseases from which silkworms suffer. One 



very deadly scourg-e termed "plag-ue" has in the past been the 
cause of immeasurable financial loss in the sericultural countries 
of both Europe and Asia, and in one country at least, namely, 
France, has been the subject of g-overnmental investig-ation. Pas- 
teur has written a book on the diseases of the silkworm. I will 
not enter into this subject further than to state that they are 
mostly of an infectious or contagious nature and that prevention 
is better than cure The hope of prevention lies in keeping- the 
worms in clean healthy surroundings, in providing- nothing but 
the best of food, and in promptly removing healthj- worms from 
the neig-hborhood of any which may be observed to be diseased or 
dead. 



16 



FRESH nULBERRY LEAVES 

Furnished in Season. 

100 Leaves, $1.00 
Mailed on receipt of Remittance. 

Dr. CECIL FRENCH, Naturalist, 

WASHINGTON. D. C. 



ft 





Anything; from a White Mouse to a White 


Elephant." 








'^HHI 


*r 


'"^"^'"'''^^B 


If you want 


''mm 


any kind of 


'^^ 


Animal or 


pinMiiMiiiiiiiir II ^^ ^'^^' ^''^'^^ 




^^S^K/^^ ^0 iTi^ for 




^*^ prices and 




||^|||r particulars 




hB^^^ No 




HB ,^ 


catalogues. 




HhmJ 


if 


WHOOPING CRANE 


This booklet, together with 100 Silkworm Eggs, 




Price 11. 00. Mailed on receipt of r 


emittance. 




Dr. CECIL FRENCH, Natur 


alist, 


Washington, D. C. 





I 




